Helicopter engine mounting system and methods

ABSTRACT

In an embodiment the system includes a method of mounting an engine in a rotary wing aircraft. The method includes providing a rotary wing aircraft having an aircraft body supported in flight through an exterior air space by a rotary wing system rotating with an operational rotating frequency (P) with a plurality of (N) rotary wings, the rotary wing aircraft body having a persistent in flight operational rotating frequency vibration. The method includes providing a first engine, the first engine for providing power to rotate the rotary wing system at the rotary wing system operational rotating frequency (P).

This patent application is a divisional application of U.S. applicationSer. No. 13/159,855, filed Jun. 14, 2011, which claims the benefit of,and incorporated by reference, U.S. Provisional Application No.61/397,607 filed on Jun. 14, 2010, both of which are incorporated hereinby reference in their entireties.

FIELD OF THE INVENTION

The invention relates to the field of rotary wing aircraft. Theinvention relates to the field of rotary wing aircraft engine mountingsystems. More particularly the invention relates to the field ofmounting aircraft engines in rotary wing aircrafts that have persistentin flight operational rotating frequency vibrations.

SUMMARY OF THE INVENTION

In an embodiment the invention includes a method of mounting an enginein a rotary wing aircraft. The method includes providing a rotary wingaircraft having an aircraft body supported in flight through an exteriorair space by a rotary wing system rotating with an operational rotatingfrequency (P) with a plurality of (N) rotary wings, the rotary wingaircraft body having a persistent in flight operational rotatingfrequency vibration. The method includes providing a first engine, thefirst engine for providing power to rotate the rotary wing system at therotary wing system operational rotating frequency (P). The methodincludes providing a top fluid chamber fluid elastomer engine mount anda bottom fluid chamber fluid elastomer engine mount, the top fluidchamber fluid elastomer engine mount having a bottom end for groundingto the aircraft body, and the bottom fluid chamber fluid elastomerengine mount having a bottom end for grounding to the aircraft body. Thetop fluid chamber fluid engine mount having a top fluid chamber distalfrom the top fluid chamber fluid engine mount bottom end, the bottomfluid chamber fluid engine mount having a bottom fluid chamber proximatethe bottom fluid chamber fluid engine mount bottom end. The methodincludes providing an intermediate cradle. The method includes providinga lateral link, the lateral link having a first end for grounding to theaircraft body and a second distal end, the second distal end distal fromthe first end. The method includes mounting the first engine to theaircraft body, with the top fluid chamber fluid elastomer engine mountbottom end grounded to the aircraft body, the bottom fluid chamber fluidelastomer engine mount bottom end grounded to the aircraft body, withthe intermediate cradle disposed between the top fluid chamber fluidelastomer engine mount and the bottom fluid chamber fluid elastomerengine mount and the first engine, with a fluid conduit connecting thetop fluid chamber fluid engine mount top fluid chamber with the bottomfluid chamber fluid engine mount bottom fluid chamber wherein the rotarywing aircraft body persistent in flight operational rotating frequencyvibration is inhibited from reaching the first engine. The mountingsystem preferably provides static determancy wherein preferably allloads can be calculated by hand calculations of force, moment, andbalance.

In an embodiment the invention includes a helicopter engine mountingsystem for mounting an engine to an aircraft body supported in flight bya rotary wing system rotating with an operational rotating frequency (P)with a plurality of (N) rotating blades, the aircraft body having apersistent in flight operational rotating frequency vibration from therotating blades. The engine mounting system includes a top fluid chamberfluid elastomer engine mount and a bottom fluid chamber fluid elastomerengine mount, the top fluid chamber fluid elastomer engine mount havinga bottom end for grounding to the aircraft body, and the bottom fluidchamber fluid elastomer engine mount having a bottom end for groundingto the aircraft body, the top fluid chamber fluid elastomer engine mounthaving a top fluid chamber distal from the top fluid chamber fluidelastomer engine mount bottom end, the bottom fluid chamber fluidelastomer engine mount having a bottom fluid chamber proximate thebottom fluid chamber fluid elastomer engine mount bottom end. The enginemounting system includes an intermediate cradle with a lateral link, thelateral link having a first end for grounding to the aircraft body and asecond distal end, the second distal end distal from the first end, thesecond distal end linked to the intermediate cradle. The top fluidchamber fluid elastomer engine mount bottom end grounded to the aircraftbody, the bottom fluid chamber fluid elastomer engine mount bottom endgrounded to the aircraft body, with the intermediate cradle disposedbetween the top fluid chamber fluid elastomer engine mount and thebottom fluid chamber fluid elastomer engine mount and the engine, with afluid conduit connecting the top fluid chamber fluid engine mount topfluid chamber with the bottom fluid chamber fluid engine mount bottomfluid chamber wherein a transfer of the persistent in flight operationalrotating frequency vibration from the aircraft body to the engine isinhibited. The mounting system preferably provides static determancywherein preferably all loads can be calculated by hand calculations offorce, moment, and balance.

In an embodiment the invention includes a method of making an enginemounting system for an engine in an aircraft body having a persistent inflight operational rotating frequency vibration. The method includesproviding a top fluid chamber fluid elastomer engine mount and a bottomfluid chamber fluid elastomer engine mount, the top fluid chamber fluidelastomer engine mount having a bottom end for grounding to the aircraftbody, and the bottom fluid chamber fluid elastomer engine mount having abottom end for grounding to the aircraft body, the top fluid chamberfluid elastomer engine mount having a top fluid chamber distal from thetop fluid chamber fluid elastomer engine mount bottom end, the bottomfluid chamber fluid elastomer engine mount having a bottom fluid chamberproximate the bottom fluid chamber fluid elastomer engine mount bottomend. The method includes providing an intermediate cradle with a centercradle revolute joint. The method includes providing a lateral link, thelateral link having a first end for grounding to the aircraft body and asecond distal end, the second distal end distal from the first end forlinking to the intermediate cradle. The method includes the intermediatecradle attachable between the engine and the top fluid chamber fluidengine mount bottom end and the bottom fluid chamber fluid engine mountbottom end with the intermediate cradle center cradle revolute jointbetween the top fluid chamber fluid engine mount and the bottom fluidchamber fluid engine mount with a fluid conduit connecting the top fluidchamber fluid engine mount top fluid chamber with the bottom fluidchamber fluid engine mount bottom fluid chamber wherein the aircraftbody persistent in flight operational rotating frequency vibration isinhibited from reaching the engine by a mass of fluid resonating betweenthe top fluid chamber fluid engine mount top fluid chamber and thebottom fluid chamber fluid engine mount bottom fluid chamber. Themounting system preferably provides static determancy wherein preferablyall loads can be calculated by hand calculations of force, moment, andbalance.

In an embodiment the invention includes an engine mount assembly formounting an engine which produces a torque to an aircraft body having apersistent troublesome frequency vibration. The engine mount assemblyincluding a first side fluid chamber fluid elastomer engine mount and asecond side fluid chamber fluid elastomer engine mount, the first sidefluid chamber fluid elastomer engine mount groundable to the body havingthe persistent troublesome frequency vibration, and the second sidefluid chamber fluid elastomer engine mount groundable to the body havingthe persistent troublesome frequency vibration, the first side fluidchamber fluid elastomer engine mount having a first fluid chamber, thesecond side fluid chamber fluid elastomer engine mount having a secondfluid chamber. The engine mount assembly including an intermediatecradle with a lateral link, the lateral link having a first end forgrounding to the body having the persistent troublesome frequencyvibration and a second distal end, the second distal end distal from thefirst end, the second distal end linked to the intermediate cradle. Thefirst side fluid chamber fluid elastomer engine mount is grounded to thebody having the persistent troublesome frequency vibration, the secondside fluid chamber fluid elastomer engine mount grounded to the bodyhaving the persistent troublesome frequency vibration, with theintermediate cradle disposed between the first fluid chamber fluidengine mount and the second side fluid chamber fluid engine mount andthe engine, with a fluid conduit connecting the first side fluid chamberfluid engine mount fluid chamber with the second side fluid chamberfluid engine mount fluid chamber wherein the torque generates a positivefluid pressure within the fluid chambers and the fluid conduit and theintermediate cradle has an intermediate cradle center cradle jointbetween the first side fluid chamber fluid elastomer engine mount andthe second side fluid chamber fluid elastomer engine mount with thefirst side fluid chamber fluid elastomer engine mount and the secondside fluid chamber fluid elastomer engine mount sharing a plurality ofloads while a transfer of the persistent troublesome frequency vibrationfrom the body to the engine is inhibited. The mounting system preferablyprovides static determancy wherein preferably all loads can becalculated by hand calculations of force, moment, and balance.

In an embodiment the invention includes a method of making a mountingsystem for mounting a subject. The method includes providing a top fluidchamber fluid mount and a bottom fluid chamber fluid mount, said topfluid chamber fluid mount having a bottom end for grounding to a body,and said bottom fluid chamber fluid mount having a bottom end forgrounding to said body, said top fluid chamber fluid mount having a topfluid chamber distal from said top fluid chamber fluid mount bottom end,said bottom fluid chamber fluid mount having a bottom fluid chamberproximate said bottom fluid chamber fluid mount bottom end. The methodincludes providing an intermediate cradle with a center cradle revolutejoint. The method includes providing a lateral link, said lateral linkhaving a first end for grounding to said body and a second distal end,said second distal end distal from said first end for linking to saidintermediate cradle, said intermediate cradle attachable between saidsubject and said top fluid chamber fluid mount and said bottom fluidchamber fluid mount with said intermediate cradle center cradle revolutejoint between said top fluid chamber fluid mount and said bottom fluidchamber fluid mount with a fluid conduit connecting said top fluidchamber fluid mount top fluid chamber with said bottom fluid chamberfluid mount bottom fluid chamber wherein frequency notch vibrations areinhibited from transmission through said mounting system mounting saidsubject to said body by a mass of fluid moving between said top fluidchamber fluid mount top fluid chamber and said bottom fluid chamberfluid mount bottom fluid chamber. The mounting system preferablyprovides static determancy wherein preferably all loads can becalculated by hand calculations of force, moment, and balance.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary of the invention, andare intended to provide an overview or framework for understanding thenature and character of the invention as it is claimed. The accompanyingdrawings are included to provide a further understanding of theinvention, and are incorporated in and constitute a part of thisspecification. The drawings illustrate various embodiments of theinvention, and together with the description serve to explain theprincipals and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an engine mounting system.

FIG. 2 illustrates a rotary wing aircraft engine mounting system withthe engine mounting system center line oriented in relationship to thefore and aft of the helicopter.

FIG. 3 illustrates a rotary wing aircraft engine mounting system.

FIG. 4 illustrates the rotary wing aircraft engine mounting system andshows the vertical, lateral, fore/aft and torque orientations of theengine mounting system in the aircraft.

FIG. 5 illustrates the engine mounting system and shows the toqueloading of connected fluid mounts and an internal cross section of afluid mount.

FIG. 6 illustrates the engine mounting system and shows the toqueloading of connected fluid mounts and cross sections of the twoconnected fluid mounts and the movement of fluid between the connectedfluid mounts.

FIG. 7 illustrates two connected fluid mounts with a 1 G static forceapplied.

FIG. 8 illustrates a fluid mount and shows fluid motion in the fluidconduit.

FIG. 9 illustrates the mounting system with the mounting system jointsand hinge lines.

FIG. 10 illustrates the attachment of the fluid mount and fluid mountinternals.

FIG. 11 illustrates a four bar system of the mounting system providinglateral stiffness.

FIG. 12 illustrates a lateral link of the mounting system.

FIG. 13 illustrates waiting fail safes of an engine mounting system.

FIG. 14 is a graph of measured test data from a mounting system showingdynamic stiffness vs. frequency and the engine mount notch frequency.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Additional features and advantages of the invention will be set forth inthe detailed description which follows, and in part will be readilyapparent to those skilled in the art from that description or recognizedby practicing the invention as described herein, including the detaileddescription which follows, the claims, as well as the appended drawings.

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings.

In an embodiment the invention includes a method of mounting a subjectengine 50 in a rotary wing aircraft 52. The method includes providing arotary wing aircraft 52 having an aircraft body 54 supported in flightthrough an exterior air space by a rotary wing system 56 rotating withan operational rotating frequency (P) with a plurality of (N) rotarywings 58, the rotary wing aircraft body 54 having a persistent in flightoperational rotating frequency vibration. The method includes providinga first subject engine 50, the first engine 50 for providing power torotate the rotary wing system 56 at the rotary wing system operationalrotating frequency (P). The method includes providing a top fluidchamber fluid elastomer engine mount 60 t and a bottom fluid chamberfluid elastomer engine mount 60 b, the top fluid chamber fluid elastomerengine mount 60 t having a bottom end 62 for grounding to the aircraftbody 54, and the bottom fluid chamber fluid elastomer engine mount 60 bhaving a bottom end 62 for grounding to the aircraft body 54. The topfluid chamber fluid engine mount 60 t having a top fluid chamber 64 tdistal from the top fluid chamber fluid mount bottom end 62, the bottomfluid chamber fluid engine mount 60 b having a bottom fluid chamber 64 bproximate the bottom fluid chamber fluid engine mount bottom end 62. Themethod includes providing an intermediate cradle 65, preferably with afirst right cradle half 6 and a second left cradle half 5. The methodincludes providing a lateral link 4, the lateral link 4 having a firstend 68 a for grounding to the aircraft body 54 and a second distal end68 c, the second distal end 68 c distal from the first end 68 a. Themethod includes mounting the first engine 50 to the aircraft body 54,with the top fluid chamber fluid elastomer engine mount bottom end 62grounded to the aircraft body 54, the bottom fluid chamber fluidelastomer engine mount bottom end 62 grounded to the aircraft body 54,with the intermediate cradle 65 disposed between the top fluid chamberfluid elastomer engine mount 60 t and the bottom fluid chamber fluidelastomer engine mount 60 b and the first engine 50, with a fluidconduit 70 connecting the top fluid chamber fluid engine mount top fluidchamber 64 t with the bottom fluid chamber fluid engine mount bottomfluid chamber 64 b wherein the rotary wing aircraft body persistent inflight operational rotating frequency vibration is inhibited fromreaching the first engine 50.

Preferably the method includes attaching the lateral link first end 68 ato the aircraft body 54 and attaching the second distal end 68 c to theintermediate cradle 65. Preferably the second distal end 68 c isattached to the intermediate cradle 65 between the top fluid chamberfluid engine mount 60 t and the bottom fluid chamber fluid engine mount60 b, preferably proximate a midpoint between the mounts 60, preferablyproximate a cradle joint 9 (preferably with cradle joint 9 connectingthe cradle halfs 6,5), preferably with a lateral link joint 10.

Preferably the method includes disposing at least a first scissor link72 between the intermediate cradle 65 and the first engine 50.Preferably a first scissor link 72 is provided for linking theintermediate cradle first upper arm 74 to the engine 50 and a secondscissor link 72′ is provided for linking the intermediate cradle secondupper arm 74′ to the engine 50. Preferably the scissor links arecomprised of an upper scissor link 2 and a lower scissor link 3.

Preferably the at least first scissor link 72 is attached to theintermediate cradle arm 74 and an engine frame 76 of the first engine50, preferably with a cradle to scissor link joint 8, preferably withthe cradle to scissor link joints 8 are comprised of a spherical jointbetween the cradle upper arm end and the scissor link with upper scissorlink 2 and lower scissor link 3. Preferably the scissors links areconnected with the engine 50 and its engine frame 76 with scissor linkto engine joints 11, and preferably a scissor link eye bolt 12.Preferably the system 1 includes failsafes 13, preferably waitingfailsafes 13 between the cradle 65 and the engine frame 76. Preferablythe failsafe 13 are comprise of a failsafe pin received inside afailsafe hole, with a failsafe clearance between the pin and holeprovising for the fail safe to be nonconnected and waiting to connectand engage each other upon a failure.

Preferably the intermediate cradle 65 is comprised of the cradle halfs6,5 joined together with cradle joint 9, preferably with intermediatecradle center cradle joint 9 comprised of a center cradle revolutejoint.

Preferably the intermediate cradle center cradle joint 9 is a revolutejoint disposed between the top fluid chamber fluid engine mount 60 t andthe bottom fluid chamber fluid engine mount 60 b. Preferably with themethod static determinacy is provided for the engine mounting system 1.

Preferably the lateral link second distal end 68 c is attached to theintermediate cradle 65 proximate the center cradle joint 9, preferablybetween the top fluid chamber fluid engine mount 60 t and the bottomfluid chamber fluid engine mount 60 b, and between the engine frame 76and the aircraft body 54.

Preferably the lateral link second distal end 68 c is attached to theintermediate cradle 65 proximate the center cradle joint 9 through anelastomer 78.

Preferably the method includes attaching the intermediate cradle 65 tothe top fluid chamber fluid engine mount 60 t with a revolute joint 7providing a mount to cradle joint and attaching the intermediate cradle65 to the bottom fluid chamber fluid engine mount 60 b with a revolutejoint 7 providing a mount to cradle joint.

Preferably the engine 50 has a longitudinally extending center line 80,the longitudinally extending center line extending longitudinally foreand aft in the aircraft 52, with an intermediate cradle center cradlejoint 9 oriented relative to the longitudinally extending center line80, with the intermediate cradle center cradle joint 9 disposed betweenthe top fluid chamber fluid engine mount 60 t and the bottom fluidchamber fluid engine mount 60 b, preferably with static determinacyprovided for the engine mounting system 1.

Preferably the method includes providing a plurality of spherical joints100 to provide an engine mount system fore/aft degree of freedom,preferably with a lower hinge line 101 and an upper hinge line 101.

Preferably the method includes providing a pressure sensor 102 forsensing the pressure of the fluid 90.

Preferably with the intermediate cradle 65 is disposed between the topfluid chamber fluid elastomer engine mount 60 t and the bottom fluidchamber fluid elastomer engine mount 60 b and the first engine 50, withthe fluid conduit 70 connecting the top fluid chamber fluid engine mounttop fluid chamber 64 t with the bottom fluid chamber fluid engine mountbottom fluid chamber 64 b the fluid 90 in the mounts and conduitoscillates back and forth and is tuned in relationship to the frequencyof the rotary wing aircraft body persistent in flight operationalrotating frequency vibration to provide a engine mount notch frequency98 centered about the in flight operational rotating frequency vibrationNP with transmission of such in flight operational rotating frequencyvibration NP through the engine mounting system 1 from the aircraft body54 into the engine 50 inhibited. In a preferred embodiment with ahelicopter with seven rotating blades the notch 98 frequency is centeredabout 21 Hz with the operational rotating frequency (P) of thehelicopter about 3 Hz producing persistent in flight operationalrotating frequency vibration from the rotating blades in the aircraftbody 54 centered about 21 Hz. In a preferred embodiment the notch 98frequency is tuned and centered about 19.5 Hz with the notchsubstantially including 21 Hz. The Dynamic Stiffness vs Frequency (K*)plot of Frequency (Hz) on the x axis and K* (lb/in) on the y axis is aplot of measured test data for a system 1 tuned at about 19.5 Hz. Thevariable volume of the chambers 64 t,64 b from the variable position ofthe cradle attachment bushing 82 relative to the mount bottom end 62provided with the bonded elastomer 84 bonded between the mountnonelastomeric inner member 86 and the mount nonelastomeric outer member88 pump and oscillate the inertia fluid 90 back and forth between thechambers 64 t,64 b through the inertia fluid conduit 70. The pumping andoscillating of the inertia fluid 90 back and forth between the chambers64 t,64 b through the inertia fluid conduit 70 preferably generatesfluid inertia forces for changing the mount operating characteristics atthe persistent in flight operational rotating frequency vibration fromthe rotating blades in the aircraft wherein the rotary wing aircraftbody persistent in flight operational rotating frequency vibration isinhibited from reaching the first engine 50 with the variable volumechambers 64 t,64 b and the variable position of the cradle attachmentbushing 82 relative to the mount bottom end 62 inhibiting thetransmission of the rotary wing aircraft body persistent in flightoperational rotating frequency vibration from the body 54 up into theengine 50. Preferably the inner member 86 has an upper and a lowerconcavity 92. Preferably in the top fluid chamber fluid elastomer enginemount 60 t the upper concavity 92 provides fluid chamber 64 t andcontains fluid 90 and the lower concavity 92 does not provide a fluidchamber and does not contain a fluid 90. Preferably in the bottom fluidchamber fluid elastomer engine mount 60 b the lower concavity 92provides fluid chamber 64 b and contains fluid 90 and the upperconcavity 92 does not provide a fluid chamber and does not contain afluid 90. Preferably the conduit 70 provides an inertia track for thefluid 90 that confines and directs the fluid between the variable volumeof the chambers 64 t,64 b. The oscillation of the fluid 90 within theinertia track conduit 70 provides an inertence mass like resistance tothe mount inner member outer member pumping forces which is in phasewith the input disturbance displacement and opposite in direction to theinput acceleration. The inertial forces of the oscillating fluid reducesthe dynamic stiffness of the mounts 60 at the predetermined frequency ofthe persistent in flight operational rotating frequency vibration fromthe rotating blades in the aircraft. In preferred embodiments differentlengths (at least a first length and at least a second length) of theconduit 70 are provided to tune the inertial forces of the oscillatingfluid in the conduit to tune the oscillating fluid reduced dynamicstiffness of the mounts 64 to correlate with the frequency of thepersistent in flight operational rotating frequency vibration from therotating blades in the aircraft.

Preferably the mount bottom ends 62 are connected and grounded to theaircraft body 54 with mount to airframe body grounding joints 14-1,14-2.Preferably top fluid mount 60 t is protected from heat by a heat shield15. Preferably bottom fluid mount 60 b is protected from heat by a heatshield 16.

In an embodiment the invention includes a helicopter engine mountingsystem 1 for mounting an engine 50 to an aircraft body 54 supported inflight by a rotary wing system 56 rotating with an operational rotatingfrequency (P) with a plurality of (N) rotating blades 58, the aircraftbody 54 having a persistent in flight operational rotating frequencyvibration from the rotating blades 58. The engine mounting systemincludes a top fluid chamber fluid elastomer engine mount 60 t and abottom fluid chamber fluid elastomer engine mount 60 b, the top fluidchamber fluid elastomer engine mount 60 t having a bottom end 62 forgrounding to the aircraft body 54, and the bottom fluid chamber fluidelastomer engine mount 60 b having a bottom end 62 for grounding to theaircraft body 54, the top fluid chamber fluid elastomer engine mounthaving a top fluid chamber 64 t distal from the top fluid chamber fluidelastomer engine mount bottom end 62, the bottom fluid chamber fluidelastomer engine mount having a bottom fluid chamber 64 b proximate thebottom fluid chamber fluid elastomer engine mount bottom end 62. Theengine mounting system 1 includes an intermediate cradle 65 with alateral link 4, the lateral link 4 having a first end 68 a for groundingto the aircraft body 54 and a second distal end 68 c, the second distalend 68 c distal from the first end 68 a, the second distal end 68 clinked to the intermediate cradle 65. The top fluid chamber fluidelastomer engine mount bottom end 62 grounded to the aircraft body 54,the bottom fluid chamber fluid elastomer engine mount bottom end 62grounded to the aircraft body 54, with the intermediate cradle 65disposed between the top fluid chamber fluid elastomer engine mount 60 tand the bottom fluid chamber fluid elastomer engine mount 60 b and theengine 50, with a fluid conduit 70 connecting the top fluid chamberfluid engine mount top fluid chamber 64 t with the bottom fluid chamberfluid engine mount bottom fluid chamber 64 b wherein a transfer of thepersistent in flight operational rotating frequency vibration from theaircraft body 54 to the engine 50 is inhibited. The variable volume ofthe chambers 64 t,64 b from the variable position of the cradleattachment bushing 82 relative to the mount bottom end 62 provided withthe bonded elastomer 84 bonded between the mount inner member 86 and themount outer member 88 pump and oscillate the inertia fluid 90 back andforth between the chambers 64 t,64 b through the inertia fluid conduit70. The pumping and oscillating of the inertia fluid 90 back and forthbetween the chambers 64 t,64 b through the inertia fluid conduit 70preferably generates fluid inertia forces for changing the mountoperating characteristics at the persistent in flight operationalrotating frequency vibration from the rotating blades in the aircraftwherein the rotary wing aircraft body persistent in flight operationalrotating frequency vibration is inhibited from reaching the first engine50 with the variable volume chambers 64 t,64 b and the variable positionof the cradle attachment bushing 82 relative to the mount bottom end 62inhibiting the transmission of the rotary wing aircraft body persistentin flight operational rotating frequency vibration from the body 54 upinto the engine 50. Preferably the inner member 86 has an upper and alower concavity 92. Preferably in the top fluid chamber fluid elastomerengine mount 60 t the upper concavity 92 provides fluid chamber 64 t andthe lower concavity 92 does not provide a fluid chamber. Preferably inthe bottom fluid chamber fluid elastomer engine mount 60 b the lowerconcavity 92 provides fluid chamber 64 b and the upper concavity 92 doesnot provide a fluid chamber. Preferably the conduit 70 provides aninertia track for the fluid 90 that confines and directs the fluidbetween the variable volume of the chambers 64 t,64 b. The oscillationof the fluid 90 within the inertia track conduit 70 provides aninertence mass like resistance to the mount inner member outer memberpumping forces which is in phase with the input disturbance displacementand opposite in direction to the input acceleration. The inertial forcesof the oscillating fluid reduces the dynamic stiffness of the mounts 64at the predetermined frequency of the persistent in flight operationalrotating frequency vibration from the rotating blades in the aircraft.In preferred embodiments different lengths (at least a first length andat least a second length) of the conduit 70 are provided to tune theinertial forces of the oscillating fluid in the conduit to tune theoscillating fluid reduced dynamic stiffness of the mounts 64 tocorrelate with the frequency of the persistent in flight operationalrotating frequency vibration from the rotating blades in the aircraft.

Preferably the lateral link second distal end 68 c is attached to theintermediate cradle 65 between the top fluid chamber fluid engine mount60 t and the bottom fluid chamber fluid engine mount 60 b.

Preferably the system 1 includes at least a first scissor link 72between the intermediate cradle 65 and the engine 50.

Preferably the at least first scissor link 72 is attached to theintermediate cradle 65 and an encircling engine frame 76 of the engine50, preferably with a spherical joint 100 between cradle upper arm endand scissor link with upper scissor link 2 and lower scissor link 3.

Preferably the engine 50 has a longitudinally extending center line 80,the longitudinally extending center line 80 extending longitudinallyfore and aft in the aircraft 52, and the intermediate cradle 65 includesa center cradle revolute joint 9 oriented relative to the longitudinallyextending center line 80.

Preferably the intermediate cradle center cradle joint 9 is a revolutejoint disposed below the longitudinally extending center line 80 andbetween the top fluid chamber fluid engine mount 60 t and the bottomfluid chamber fluid engine mount 60 b, preferably with staticdeterminacy provided for the engine mounting system 1.

Preferably the lateral link second distal end 68 c is attached to theintermediate cradle 65 proximate the center cradle joint 9. Preferablythe lateral link second distal end 68 c is attached between the topfluid chamber fluid engine mount 60 t and the bottom fluid chamber fluidengine mount 60 b, and between the engine frame 76 and the aircraft body54. Preferably the lateral link second distal end 68 c is attached tothe intermediate cradle 65 proximate the center cradle joint 9 throughan elastomer 78.

Preferably the intermediate cradle 65 is attached to the top fluidchamber fluid engine mount 60 t with a revolute joint 7 and is attachedto the bottom fluid chamber fluid engine mount 60 b with a revolutejoint 7.

Preferably the engine 50 has a longitudinally extending center line 80,the longitudinally extending center line 80 extending longitudinallyfore and aft in the aircraft 52, with an intermediate cradle centercradle joint 9 oriented relative to the longitudinally extending centerline 80, with the intermediate cradle center cradle joint 9 disposedbetween the top fluid chamber fluid engine mount 60 t and the bottomfluid chamber fluid engine mount 60 b. Preferably static determinacy isprovided for the engine mounting system 1.

Preferably the system includes a plurality of spherical joints 100 toprovide an engine mount system fore/aft degree of freedom, preferablywith a lower hinge line 101 and an upper hinge line 101.

Preferably the system includes a pressure sensor 102 for sensing thepressure of the fluid 90.

Preferably with the system 1 the intermediate cradle 65 is disposedbetween the top fluid chamber fluid elastomer engine mount 60 t and thebottom fluid chamber fluid elastomer engine mount 60 b and the firstengine 50, with the fluid conduit 70 connecting the top fluid chamberfluid engine mount top fluid chamber 64 t with the bottom fluid chamberfluid engine mount bottom fluid chamber 64 b with the fluid 90 in themounts 60 and conduit 70 oscillating back and forth in a tunedrelationship with the frequency of the rotary wing aircraft bodypersistent in flight operational rotating frequency vibration to providea engine mount notch frequency 98 centered about the in flightoperational rotating frequency vibration NP with transmission of such inflight operational rotating frequency vibration NP through the enginemounting system 1 in a direction from the aircraft body 54 into theengine 50 inhibited. In a preferred embodiment with a helicopter 52 withseven rotating blades 58 the notch 98 frequency is centered about 21 Hzwith the operational rotating frequency (P) of the helicopter 52 about 3Hz producing persistent in flight operational rotating frequencyvibration from the rotating blades 58 in the aircraft body 54 centeredabout 21 Hz. In a preferred embodiment the notch 98 frequency is tunedand centered about 19.5 Hz with the notch substantially including 21 Hz.The Dynamic Stiffness vs Frequency (K*) plot of Frequency (Hz) on the xaxis and K* (lb/in) on the y axis is a plot of measured test data for asystem 1 tuned at about 19.5 Hz.

In an embodiment the invention includes a method of making an enginemounting system 1 for an engine 50 in an aircraft body 54 having apersistent in flight operational rotating frequency vibration. Themethod includes providing a top fluid chamber fluid elastomer enginemount 60 t and a bottom fluid chamber fluid elastomer engine mount 60 b,the top fluid chamber fluid elastomer engine mount 60 t having a bottomend 62 for grounding to the aircraft body 54, and the bottom fluidchamber fluid elastomer engine mount 60 b having a bottom end 62 forgrounding to the aircraft body 54, the top fluid chamber fluid elastomerengine mount 60 t having a top fluid chamber 64 t distal from the topfluid chamber fluid elastomer engine mount bottom end 62, the bottomfluid chamber fluid elastomer engine mount 60 b having a bottom fluidchamber 64 b proximate the bottom fluid chamber fluid elastomer enginemount bottom end 62. The method includes providing an intermediatecradle 65 with a center cradle revolute joint 9. The method includesproviding a lateral link 4, the lateral link 4 having a first end 68 afor grounding to the aircraft body 54 and a second distal end 68 c, thesecond distal end 68 c distal from the first end 68 a for linking to theintermediate cradle 65. The method includes the intermediate cradle 65attachable between the engine 50 and the top fluid chamber fluid enginemount bottom end 62 and the bottom fluid chamber fluid engine mountbottom end 62 with the intermediate cradle center cradle revolute joint9 between the top fluid chamber fluid engine mount 60 t and the bottomfluid chamber fluid engine mount 60 t with a fluid conduit 70 connectingthe top fluid chamber fluid engine mount top fluid chamber 64 t with thebottom fluid chamber fluid engine mount bottom fluid chamber 64 bwherein the aircraft body persistent in flight operational rotatingfrequency vibration is inhibited from reaching the engine 50 by a massof fluid 90 resonating between the top fluid chamber fluid engine mounttop fluid chamber 64 t and the bottom fluid chamber fluid engine mountbottom fluid chamber 64 b.

In a preferred embodiment with a helicopter 52 with seven rotatingblades 58 the transmission of the NP 21 Hz persistent in flightoperational rotating frequency vibration through the engine mounts 60 isinhibited by the tuned notch 98 filter of the fluid mass 90 oscillatingbetween the mounts 60 which combines in an out of phase manner with theelastomer response of the mounts, with the tuned notch 98 filter centerabout the NP 21 Hz troublesome vibration.

Preferably the intermediate cradle center cradle joint 9 is a revolutejoint disposed between the top fluid chamber fluid engine mount 60 t andthe bottom fluid chamber fluid engine mount 60 b wherein staticdeterminacy is provided for the engine mounting system 1.

Preferably the method includes attaching the second distal end 68 c ofthe link 4 to the intermediate cradle 65 through an elastomer member 78between the top fluid chamber fluid engine mount 60 t and the bottomfluid chamber fluid engine mount 60 b.

Preferably the method includes providing a first scissor link 72 and asecond scissor link 72′ between the intermediate cradle 65 and theengine 50.

Preferably the scissor links 72, 72′ are attached to the intermediatecradle 65 and an engine frame 76 of the first engine 50 with a sphericaljoint 100 between the cradle 65 and scissor link.

Preferably the lateral link second distal end 68 c is attached to theintermediate cradle 65 proximate the center cradle joint 9, preferablybetween the top fluid chamber fluid engine mount 60 t and the bottomfluid chamber fluid engine mount 60 b, and between the engine frame 76and the aircraft body 54.

Preferably the intermediate cradle 65 is attached to the top fluidchamber fluid engine mount 60 t with a revolute joint 7 and theintermediate cradle 65 is attached to the bottom fluid chamber fluidengine mount 60 b with a revolute joint 7.

Preferably the engine 50 has a longitudinally extending center line 80,the longitudinally extending center line 80 extending longitudinallyfore and aft in the aircraft 52, with the intermediate cradle centercradle joint 9 oriented relative to the longitudinally extending centerline 80, with the intermediate cradle center cradle joint 9 disposedbetween the top fluid chamber fluid engine mount 60 t and the bottomfluid chamber fluid engine mount 60 b, preferably with staticdeterminacy provided for the engine mounting system 1.

Preferably the method includes providing a plurality of spherical joints100 to provide an engine mount system fore/aft degree of freedom,preferably with a lower hinge line 101 and an upper hinge line 101.

Preferably the method includes providing a pressure sensor 102 forsensing the pressure of the fluid 90.

Preferably with the intermediate cradle 65 disposed between the topfluid chamber fluid elastomer engine mount 60 t and the bottom fluidchamber fluid elastomer engine mount 60 b and the engine 50, with thefluid conduit 70 connecting the top fluid chamber fluid engine mount topfluid chamber 64 t with the bottom fluid chamber fluid engine mountbottom fluid chamber 64 b the fluid 90 in the fluid elastomer mounts 60and conduit 70 oscillates back and forth and is tuned in relationship tothe frequency of the rotary wing aircraft body persistent in flightoperational rotating frequency vibration to provide a engine mount notch98 frequency centered about the in flight operational rotating frequencyvibration NP with transmission of such in flight operational rotatingfrequency vibration NP through the engine mounting system from theaircraft body 54 into the engine 50 inhibited. In a preferred embodimentwith a helicopter 52 with seven rotating blades 58 the notch 98frequency is centered about 21 Hz with the operational rotatingfrequency (P) of the helicopter about 3 Hz producing persistent inflight operational rotating frequency vibration from the rotating bladesin the aircraft body 54 centered about 21 Hz. In a preferred embodimentthe notch 98 frequency is tuned and centered about 19.5 Hz with thenotch substantially including 21 Hz. The Dynamic Stiffness vs Frequency(K*) plot of Frequency (Hz) on the x axis and K* (lb/in) on the y axisis a plot of measured test data for a system 1 tuned at about 19.5 Hz.

In an embodiment the invention includes a method of making a mountingsystem for mounting a subject. The method includes providing a top fluidchamber fluid mount and a bottom fluid chamber fluid mount, said topfluid chamber fluid mount having a bottom end for grounding to a body,and said bottom fluid chamber fluid mount having a bottom end forgrounding to said body, said top fluid chamber fluid mount having a topfluid chamber distal from said top fluid chamber fluid mount bottom end,said bottom fluid chamber fluid mount having a bottom fluid chamberproximate said bottom fluid chamber fluid mount bottom end. The methodincludes providing an intermediate cradle with a center cradle revolutejoint. The method includes providing a lateral link, said lateral linkhaving a first end for grounding to said body and a second distal end,said second distal end distal from said first end for linking to saidintermediate cradle, said intermediate cradle attachable between saidsubject and said top fluid chamber fluid mount and said bottom fluidchamber fluid mount with said intermediate cradle center cradle revolutejoint between said top fluid chamber fluid mount and said bottom fluidchamber fluid mount with a fluid conduit connecting said top fluidchamber fluid mount top fluid chamber with said bottom fluid chamberfluid mount bottom fluid chamber wherein frequency notch vibrations areinhibited from transmission through said mounting system mounting saidsubject to said body by a mass of fluid moving between said top fluidchamber fluid mount top fluid chamber and said bottom fluid chamberfluid mount bottom fluid chamber. The mounting system preferablyprovides static determancy wherein preferably all loads can becalculated by hand calculations of force, moment, and balance.

In an embodiment the invention includes an engine mount assembly 1 formounting a subject engine 50 which produces a torque to an aircraft body54 having a persistent troublesome frequency vibration. The engine mountassembly 1 including a first side fluid chamber fluid elastomer enginemount 60 and a second side fluid chamber fluid elastomer engine mount60, the first side fluid chamber fluid elastomer engine mount groundableto the body 54 having the persistent troublesome frequency vibration,and the second side fluid chamber fluid elastomer engine mountgroundable to the body 54 having the persistent troublesome frequencyvibration, the first side fluid chamber fluid elastomer engine mounthaving a first fluid chamber 64, the second side fluid chamber fluidelastomer engine mount having a second fluid chamber 64. The enginemount assembly including an intermediate cradle 65 with a lateral link4, the lateral link having a first end 68 a for grounding to the body 54having the persistent troublesome frequency vibration and a seconddistal end 68 c, the second distal end distal from the first end, thesecond distal end linked to the intermediate cradle 65. The first sidefluid chamber fluid elastomer engine mount 60 is grounded to the body 54having the persistent troublesome frequency vibration, the second sidefluid chamber fluid elastomer engine mount 60 grounded to the body 54having the persistent troublesome frequency vibration, with theintermediate cradle 65 disposed between the first fluid chamber fluidengine mount and the second side fluid chamber fluid engine mount andthe engine, with a fluid conduit 70 connecting the first side fluidchamber fluid engine mount fluid chamber 64 with the second side fluidchamber fluid engine mount fluid chamber 64 wherein the torque generatesa positive fluid pressure within the fluid chambers 64 and the fluidconduit and the intermediate cradle 65 has an intermediate cradle centercradle joint between the first side fluid chamber fluid elastomer enginemount and the second side fluid chamber fluid elastomer engine mountwith the first side fluid chamber fluid elastomer engine mount and thesecond side fluid chamber fluid elastomer engine mount sharing aplurality of loads while a transfer of the persistent troublesomefrequency vibration from the body 54 to the engine 50 is inhibited.

Preferably the first side fluid chamber fluid elastomer engine mount 60has a first fluid elastomer mount primary line of action 96 and thesecond side fluid chamber fluid elastomer engine mount 60 has a secondfluid elastomer mount primary line of action 96 with the first fluidelastomer mount primary line of action substantially parallel with thesecond fluid elastomer mount primary line of action.

Preferably the engine torque generating positive fluid pressure withinthe fluid chambers 64 and the fluid conduit 70 inhibits a fluidcavitation in the first side fluid chamber fluid elastomer engine mountand the second side fluid chamber fluid elastomer engine mount during aplurality of translation vibration isolation movements of the assembly.

Preferably a stiffness of the assembly 1 in a second translationdirection nonparallel with the force of gravity is controlled by thelateral link 4 with the assembly having a static determinacy.

Preferably the intermediate cradle 65 has a first side upper arm 74providing a first side engine load application point, the first sideupper arm first side engine load application point distal from theintermediate cradle center cradle joint 9 and a second side upper arm74′ providing a second side engine load application point, the secondside upper arm second side engine load application point distal from theintermediate cradle center cradle joint 9.

Preferably a first side scissor link 72 is between the first side upperarm first side engine load application point and the engine 50 and asecond side scissor link 72′ between the second side upper arm secondside engine load application point and the engine 50.

Preferably the intermediate cradle center cradle joint 9 is proximatethe body 54.

Preferably the assembly 1 and the fluid conduit 70 and the first sidefluid chamber fluid elastomer engine mount 60 and the second side fluidchamber fluid elastomer engine mount 60 are free of a fluid volumecompensator chamber.

Preferably the assembly includes a pressure sensor 102 for sensing thepressure of the fluid 90.

Preferably the fluid elastomer engine isolation mounts 60 provide a highstiffness to torque produced by the engine 50 through the generation ofhydrostatic pressure within the fluid chambers 64 and the connectedconduit 70. Preferably at the same time the fluid elastomer engineisolation mounts 60 are soft to provide isolation in a primarytranslational direction, with the primary translational directionoriented parallel with gravity, with further reduction at the tunednotch 98 frequency. Preferably the primary translational direction isoriented parallel with gravity with this preferably being the directionof the highest static loads. Also, preferably at the same time thenatural 1 G of load that is always present as a mean. To minimizedeflections of the supported engine 50 higher stiffness is provided inthe gravity direction as opposed to the perpendicular (non-parallel togravity) direction with this higher stiffness preferably limitingdeflections results with the tuned notch 98 frequency reducing thestiffness reduction in that direction at the persistent in flightoperational rotating frequency vibration wherein a transmission of thepersistent troublesome frequency vibration from the body 54 through themounts 60 and into the engine 50 is inhibited.

Preferably the normal engine torque produces an addition of pressurewithin the mounts 60 as opposed to a negative pressure.

Preferably the two fluid elastomer engine isolation mounts 60 areoriented with their primary line of action 96 parallel with each other,and parallel with the primary maneuver load direction.

Preferably the positive hydrostatic pressure that is produced by theengine torque reaction generates fluid pressure to inhibit cavitation inthe two fluid elastomer engine isolation mounts 60 due to fluctuationsof dynamic pressures due to translational vibration isolation movements.

Preferably the two fluid elastomer engine isolation mounts isolators 60,cradle 65, and associated joints, provide a system/assembly/methodwherein the stiffness in the second translational direction (preferablyperpendicular to gravity) is controlled by the lateral link 4,preferably only by the lateral link 4 itself. Preferably this 4-barsystem/assembly/method provides static determinacy for the engineisolation mounting system 1.

Preferably the center joint 9 in the intermediate cradle 65 providesfreedom for engine 50 thermal growth, and tolerance stack, andpreferably at the same time forces the first side and second side cradlehalves 6,5 to share loads produced by aircraft maneuvers in the lateraland vertical directions and inhibits all lateral loads being supportedon only one side of the engine 50.

Preferably the center cradle joint 9 is located distal and mostpreferably at an extreme distance as far from the engine loadapplication point as possible. Preferably the center cradle joint 9 andthe distal first side upper arm first side engine load application point174 and the second side upper arm second side engine load applicationpoint 174′ inhibits the amount of radial load produced on the engineattachment points due to aircraft maneuvers and torque.

Preferably the system/assembly/methods protect the engine 50 from theaircraft body persistent troublesome frequency vibration inducedexcitation at 21 Hz. That persistent troublesome frequency excitationwhich the system/assembly/methods inhibit the transmission of isproduced by the 7 P vibration of the main rotor of the helicopter and istransmitted throughout the airframe body 54.

The engine system/assembly/methods provide controlled stiffness that canbe effectively sized and tuned to provide frequency placement andisolation. Preferably the rigid body modes of the engine 50 relative tothe aircraft body 54 are maintained within the 8-15 Hz bandwidth, andwith the torsional/roll modes close to 15 Hz, or above 27 Hz.Dynamically this preferably provides effective isolation of the 21 Hzexcitation.

The engine system/assembly/methods utilize the mass of fluid 90 that isadjustable. With the mass of fluid 90 adjustable in the system/assembly,such as with adjustments to the fluid volume in the conduit 70 or fluiddensity of fluid 90, the system/assembly is tunable to effectivelycreate a notch 98 in the dynamic stiffness at a specified frequency.This preferably provides a statically stiff system 1 which contains adynamic notch 98 in response; and in a preferred seven blade helicopterembodiment tuned at about 21 Hz. In a preferred embodiment the notch 98frequency is tuned and centered about 19.5 Hz with the notchsubstantially including 21 Hz. The Dynamic Stiffness vs Frequency (K*)plot of Frequency (Hz) on the x axis and K* (lb/in) on the y axis is aplot of measured test data for a system 1 tuned at about 19.5 Hz.

The engine system/assembly/methods provide a statically stiff anddynamically soft isolator system 1. Preferably the isolator 1 uses atuned fluid mass 90 to create a notch 98 filter at a specified preferredfrequency. The engine system/assembly mounts 60 have fluid chambers andpassages for a small amount of fluid and takes advantage of thehydraulic pumping action of the bonded elastomer sections 84 and innermember 86 to transfer the fluid between the mounts. The response of thefluid 90 is tuned so that it combines in an out-of-phase manner with theelastomer response of bonded elastomer sections 84, resulting inincreased vibration isolation at a given frequency. The enginesystem/assembly isolator mounts 60 provide for placement of the notch 98frequency, Fnotch, at a desired frequency which coincides with a maximumtonal excitation band. In a preferred helicopter embodiment the mounts60, conduit 70 and fluid inertia 90 are tuned to provide the notch 98 atthe 7 P excitation frequency of 21 Hz. In a preferred embodiment thenotch 98 frequency is tuned and centered about 19.5 Hz with the notchsubstantially including 21 Hz. The Dynamic Stiffness vs Frequency (K*)plot of Frequency (Hz) on the x axis and K* (lb/in) on the y axis is aplot of measured test data for a system 1 tuned at about 19.5 Hz.

Preferably the system/assembly/methods utilize a high-pressure, braided,fluid hose as a fluid conduit 70 connected between the two fluidchambers 64. The mounts 60 are preferably installed inverted withrespect to each other. Preferably one mount contains a fluid volume ontop, while the other is on the bottom. As the engine isolation mountsystem 1 reacts torque, the fluid 90 is compressed within both mounts 60and the hose conduit 70. This state of hydrostatic compression providesa very high effective stiffness to react the torsional load. The abilityto tune is preferably provided by adjustments chosen from the tuningadjustment character group comprise of elastomer section thickness,elastomer modulus, fluid density, piston area, hose area, hose length(conduit interia track length), volume stiffness and combinations ofsuch tuning adjustment characters.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the invention withoutdeparting from the spirit and scope of the invention. Thus, it isintended that the invention cover the modifications and variations ofthis invention provided they come within the scope of the appendedclaims and their equivalents. It is intended that the scope of differingterms or phrases in the claims may be fulfilled by the same or differentstructure(s) or step(s).

The invention claimed is:
 1. A helicopter engine mounting system formounting an engine to an aircraft body supported in flight by a rotarywing system rotating with an operational rotating frequency (P) with aplurality of (N) rotating blades, said aircraft body having a persistentin flight operational rotating frequency vibration from said rotatingblades, said engine mounting system including a top fluid chamber fluidengine mount and a bottom fluid chamber fluid engine mount, said topfluid chamber fluid engine mount having a bottom end for grounding tosaid aircraft body, and said bottom fluid chamber fluid engine mounthaving a bottom end for grounding to said aircraft body, said top fluidchamber fluid engine mount having a top fluid chamber distal from saidtop fluid chamber fluid engine mount bottom end, said bottom fluidchamber fluid engine mount having a bottom fluid chamber proximate saidbottom fluid chamber fluid engine mount bottom end, an intermediatecradle with a lateral link, said lateral link having a first end forgrounding to said aircraft body and a second distal end, said seconddistal end distal from said first end, said second distal end linked tosaid intermediate cradle, said top fluid chamber fluid engine mountbottom end grounded to said aircraft body, said bottom fluid chamberfluid engine mount bottom end grounded to said aircraft body, with saidintermediate cradle disposed between said top fluid chamber fluid enginemount and said bottom fluid chamber fluid engine mount and said engine,with a fluid conduit connecting said top fluid chamber fluid enginemount top fluid chamber with said bottom fluid chamber fluid enginemount bottom fluid chamber wherein a transfer of said persistent inflight operational rotating frequency vibration from said aircraft bodyto said engine is inhibited.
 2. A system as claimed in claim 1 whereinsaid lateral link second distal end is attached to said intermediatecradle between said top fluid chamber fluid engine mount and said bottomfluid chamber fluid engine mount.
 3. A system as claimed in claim 1including at least a first scissor link between said intermediate cradleand said engine.
 4. A system as claimed in claim 3 wherein said at leastfirst scissor link is attached to said intermediate cradle and anencircling engine frame of said engine.
 5. A system as claimed in claim1 wherein said engine has a longitudinally extending center line, saidlongitudinally extending center line extending longitudinally fore andaft in said aircraft, and said intermediate cradle includes a centercradle joint oriented relative to said longitudinally extending centerline.
 6. A system as claimed in claim 5 wherein said intermediate cradlecenter cradle joint is a revolute joint disposed below saidlongitudinally extending center line and between said top fluid chamberfluid engine mount and said bottom fluid chamber fluid engine mount. 7.A system as claimed in claim 6 wherein said lateral link second distalend is attached to said intermediate cradle proximate said center cradlejoint.
 8. A system as claimed in claim 1 including with saidintermediate cradle attached to said top fluid chamber fluid enginemount with a revolute joint and said intermediate cradle attached tosaid bottom fluid chamber fluid engine mount with a revolute joint.
 9. Asystem as claimed in claim 1, said engine having a longitudinallyextending center line, said longitudinally extending center lineextending longitudinally fore and aft in said aircraft, with anintermediate cradle center cradle joint oriented relative to saidlongitudinally extending center line, with said intermediate cradlecenter cradle joint disposed between said top fluid chamber fluid enginemount and said bottom fluid chamber fluid engine mount.
 10. A system asclaimed in claim 1 including a plurality of spherical joints to providean engine mount system fore and aft degree of freedom.
 11. A system asclaimed in claim 1 including a pressure sensor for sensing the pressureof said fluid.
 12. A system as claimed in claim 1 wherein saidintermediate cradle has an intermediate cradle center cradle joint and afirst side upper arm, said first side upper arm providing a first sideengine load application point, said first side upper arm first sideengine load application point distal from said intermediate cradlecenter cradle joint and said intermediate cradle has a second side upperarm providing a second side engine load application point, said secondside upper arm second side engine load application point distal fromsaid intermediate cradle center cradle joint.
 13. A system as claimed inclaim 12 with a first side scissor link between said first side upperarm first side engine load application point and said engine and asecond side scissor link between said second side upper arm second sideengine load application point and said engine.
 14. A system as claimedin claim 12 wherein said intermediate cradle center cradle joint isproximate said body.
 15. A system as claimed in claim 1, said enginemounting system free of a fluid volume compensation chamber.
 16. Asystem as claimed in claim 15, wherein a torque from said enginegenerates a positive fluid pressure within said fluid chambers and saidfluid conduit.
 17. A system as claimed in claim 16 wherein said enginetorque generating positive fluid pressure within said fluid chambers andsaid fluid conduit inhibits a fluid cavitation in said fluid chambersduring a plurality of translation vibration isolation movements of saidsystem.